FWIW I'm in an HOA that owns our roads, and we do aggressive PM to hold our costs down.
We seal coat our roads about every three years, usually in the fall when the temps fall and the cracks open up, but before the snow starts. We 'touch up' as necessary in between, but always in the fall
We fill cracks bigger than about 3/16 -1/4" with an emulsion, then seal over the top with a seal coat,
The purpose of filling the cracks is to keep rainwater from getting underneath the pavement which can lead to structural failure (potholes)
The purpose of the seal coat is to provide a layer of UV protection and a thin top wear layer.
It is a little bit of a dance between filling cracks and seal coating. If you fill a crack and the crack isn't wide enough to let the emulsion flow into it, it will sit on top of the pavement and pick up with tires, especially if there are vehicles turning. On the other hand, it you let the crack grow too big and just try and fill it with the sealer, you risk water getting under the pavement and a pothole.
As a word of advise, you want to make sure your grading/draining/bar ditches are all working properly to keep water away from your pavement. When you said your cracks were near the edge of the asphalt, that was my first thought
The traffic that does the most damage to our pavement is the city's garbage trucks, especially in cul-de-sacs where they have to turn around
